It should probably be noted that Conducent ceased all operations in April or
May of this year.  Their servers no longer respond, and don't send out new
ads.  According to information I received from Conducent, all ads previously
downloaded by their software should be expired, and no longer displayed.  (I
really doubt that means the ads have been removed from the system, the user
can safely delete the files containing the ads -- actually, that was safe to
do at any time in the past, too).  It should also be noted that by disabling
tsadbot.exe, ads are still displayed, and one can still click on the ads to
get to the appropriate website (going through a re-direct on conducent's
servers).  Of course, since the servers aren't up anymore, that doesn't apply.

Specifically, with PKZIP 2.6, removing the adbot software (tsadbot.exe, and
the various ts*.dll files) would disable the ads without affecting the program.
With PKZIP for Windows 2.7, removing the adbot software would prevent the
program from running.  For version 4.0 (with the adbot), if one removes any
portion of the adbot software, PKZIP would behave as if the evaluation period
had just ended, and prompt the user to continue using the program without ads,
or to install the ad software.  To get around this, one can replace the
tsadbot.exe file with a dummy which just exits, and then replace the ct*.dll
files with dummy DLL files.  Those DLL files _must_ do much of the same work
as the real DLLs.  Otherwise, PKZIP will decide the DLLs are corrupt, and give
the same prompt described above.

It should also be noted that all the ad-enabled versions of PKZIP for Windows
indicate that the ad software is about to be installed, and gives the user a
chance to abort.  With versions of 2.6 & 2.7, this meant you also couldn't
install PKZIP for Windows.  With version 4.0, you could install PKZIP for
Windows without installing the ads.  For an evaluation period of only 10 days,
the user wouldn't see ads, and wouldn't be subjected to a rather annoying NAG.
After that period, the user had a choice of dealing with the NAG, or installing
the ad software.

Finally, anyone who wants to use PKZIP without paying for the program, and
without dealing with ads can download the latest version, which no longer
contains the ad software.  Of course, the preferred method of using PKZIP
without installing ad software is to pay for the program. :)
 

PS If any of conducent's files showed back up after being deleted (and without
the user being prompted), it's because the DLLs contained code to get the file
back again -- it certainly has nothing to do with the client program.